What is the best procedure for sighting in the Aimpoint? I have a Comp ML2 on my M4 flat top.

Is the procedure same as for a regular scope? On my 20" Hbar I sighted in that rifle with a 9 x 28 scope at 25 yards, with the bullet drop compensator set to "4". Then 3= 50 yds, 2= 75 yds, 1 = 100 yards, 2=200 yrds, 3=300 yds, etc

But the Aimpoint doesnt have a BDC, so should I just sight it in at same 25 yards?

Does the bullet trajectory on the M4 follow same general path as the 20" gun, that is, bullet rises from barrel and crosses "near zero" at 25 yards, continues to rise past 25 yards, then crosses "far zero" on the way down at 100 yards...is this what the M4 would also do?

Since these red dot sights dont have BDC's, how do you best adjust for different ranges to target?

Thanks for the help.

What I do is this.
(depending on your mount)

1) BZO the iron sights of your weapon.

2) Adjust the dot of the Aimpoint, so that when looking through the Irons, the dot sits just above the front site post.

I would reccomend actually zeroing the aimpoint.
If the dot sits at about the same height as the front sight post use a 25M zero (If you want to shoot to 300M)

If it is mounted on a carry handle you might want to zero at 50yds(as a 25M zero will leave this shooting way high at 300M and probably zeroed for 350-375M)

If your weapon is used for closer than 300meters or on targets smaller than 18x30inches

A zero 1 inch high at 50yds with a normal iron sight mounting height should give you A MUCH FLATTER 0-250 yd zero. [b]this is much more user-friendly than a 0-300meter zero that will have you shooting low at all but 300meters[/b]

thanks for tips.

my Aimpoint is on the ARMS 2268 QD with the spacer to co-witness with front site.

so if i zero at 25 yards, and the target is say at 50 yards, the rifle would be shooting high, so i'd have to place the dot below the target, right? and closer to 25 yards the gun would shoot low?

so i guess with these Aimpoints with no BDC's you have to just zero it in at "the most likely range" and then practice-practice-practice at all ranges less than or greater than the sighted in range?

Here's a really interesting article that, inter alia, touches on the BZO issue (iron and Aimpoint) as utilised by 1st Force:  [url]http://www.mca-marines.org/Gazette/2002/02Dailey.html[/url]

I've posted this at "Rifles, Uppers, Lowers, Barrels, and more" forum as well as the "General Firearms" forum, as it covers a wide range of M4 related topics.

O'DubhGhaill
Force Recon Association reg. member #2259
[url]http://www.forcerecon.com[/url]

great article. thanks.

looking at the data in Fig. 1, it shows the bullet from the 14.5" barrel is still rising towards line-of-site past the 25 yard mark, but passes line-of-site before the 50 yard mark. perhaps line-of-site intersects at about 45 yards or so.

seems like a good starting point, site in 1" low at 25 yards. should be dead nuts around 45 yards, and only .3" high at 50 yards.

okay, but my M4 is the 16" barrel (Colt MT6400C), what would this extra barrel length do to the data in Fig. 1?

Improved Battlesight Zero (IBSZ) works just as well with the dot as the iron sights, maybe better. Initial zero (and first crossover) is at 50 yards. Downrange crossover is 200 meters. Bullet remains within 2" of line of sight from about 12 to 220 meters.

Try [url]communities.msn.com/TheMarylandAR15ShootersSite/improvedbattlesightzero.msnw[/url]

-- Chuck

Hmmmmmmm...

CHUCK, great article, thanx. it re-enforces what was posted earlier, that line of sight crossover is about 50 yards and the flatness of the trajectory out to 300 yards keeps the bullet in the kill zone.

i do think it is easier to sight in at 25 yards, 1" low. thats the way i'll proceed.

then set up at 50 and see if its dead nuts.

Put yourself "on the paper" at 25 yards an inch low and tune it at 50 yards.  

If at all possible shoot at 200 meters and make any corrections you need.  

With a 4 MOA dot and you doing your part all the bullets should be inside the dot out to 220 meters.  Someone coined the term [i]Red Dot of Death (tm)[/i].

Zero the rear sight iron sight (on your handle) at the same 50 yards and you'll shoot the same zero all the time.  Reset your rear iron sight to bottom out at 6/3 -4 clicks if you want the numbers to be meaningful.  If you don't care don't reset it.

-- Chuck

dont have BUIS yet but plan to go with the ARMS #40.

do all these procedures also aply to my 20" Hbar? reason i ask is because i already sighted it in to zero (not 1" low) at 25 yards, then i use the BDC (bullet drop compensator) on my 9 x 28 scope to make adjustments for ranging.

IBSZ works on the 20" bbl too.  Not sure how well the irons shoot at 400 or 500 meters, though.

-- Chuck